Speed-control mechanism



April 19, 1927.

J. E. RENHOLDT SPEED CONTROL MECHANISM Filed May 29- 1924 w R M r H 5 MN v% m W Patented Apr. 1 9, 192].

UNITED STATES wastes PATENT OFFICE.

JOHN E. RENI-IOLD'I, or STRATFORD, CONNECTICUT, ASSiGNOR To DTCTAEPHONECOR- ronarrou, or BRIDGEPORT, oonn'nc'rrcu'r, A CORPORATION OF NEW YORK.

SPEED-CONTROL MECHA NISM.

Application filed May 29, 1924. Serial No. 716,674.

This invention relates to speed control mechanism, and more particularly, to speed control mechanism for phon'ographs.

In the accompanying drawings, which illustrate one embodiment of the present invention,

Figure 1 is a perspective view of the speed regulating unit made in accordance with the present invention, showing part of the motor-frame and the brake-disc for the motor, in dotted lines.

Fig. 2 is a top plan view showing the speed controlling device of the present invention as mounted upon the motor frame of a. phonograph motor.

Fig. 3 is a front elevation of the parts shown in Fig. 2, showing the manually operated part of the control mechanism in the remote, relatively inaccessible position which it occupies in the dictating type of dictation machine. 2

Fig. 4 is a view similar to Fig. 8, showing the manually operable part of the control mechanism in accessible position upon the motor board where it is preferably 10-- cated on the transcribing machine.

Figs. 5 and 6 are detail views. 7

As shown in the accompanying drawings, the motor-casing 10 is mounted upon and forms part of a frame 11 which is preferably suspended by springs 12 upon the top 13 of the phonograph, so that vibrations of the motor and parts connected thereto will not be transmitted to the top 13 and thus to the sound recording or reproducing mechanism. This spring suspension of the motorframe allows it to have movement relative to the top 13 which relative movement has an important bearing upon the speed control mechanism for the motor as hereinafter pointed out.

For controlling the speed of the motor, the motor shaft 14, in the embodiment of the invention herein shown, is provided with a speed-governor comprising a plurality of weights 15 mounted on bow-springs 16 connected at one end to a sliding collar 17 carrying a brakedisk 18. When the shaft is rotated the weights 18 are thrown outwardly centrifugal .force and this causes the springs 16 to bow and draw the brake-disk outwardly from the motor, the other ends of the bow-springs 16 being anchored to the shaft 14: by a collar not shown. The extent of traveling movement of the brake-disk 18 to the right, as seen in Fig.4, is controlled by the centrifugal force developed in the weights 15, assuming that the brake-disk 18 is free to move.

By opposing the traveling movement of the brake-disk 18, the speed of the shaft 14 of the motor can be varied, since the pressure of the brake-disk against the means opposing its movement produces suflicient friction to retard the rotation of the brakedisk. The amount of traveling movement allowed to the brake-disk 18, therefore, determines the speed at which the motor may operate, according to a predetermined plan.

For the purpose of opposing the traveling movement of the brake-disk 18, there is usually provided a braking mechanism, which, in the form herein shown, comprises a pair of pads 19, whose position may be manually controlled. Usually the pads 19 are suitably supported on the top 13 of the phonograph and the supporting mechanism is movable manually to vary the position of the pads. But, this arrangement Of the supportingmeans for the pads 19 is not ad vantageo-us because the vibrations of the motor may then be transmitted to the top 13 through the supporting means for the pad, and also because of difficulties produced by the relative movement between the motor frame and the top-board 13 above referred To avoid these difiiculties, the pads 19, in

accordance with the present invention, are

instead supported by the motor-frame 11.

In the preferred form of this invention, that shown in the accompanying drawings, the pads 19 are carried by a yoke 20 having a pivotal connection 21 to a shifting-lever 22. The shifting-lever 22 is preferably fulcrumed on a stud 23 on a plate 24 which is secured directly to the motor frame 11 by means of the bolts 24 which are utilized to secure the springs 12 to the motor frame, the plate 24 being perforated at 25 to allow the bolts 241 to pass through the plate 2 1.

The shifting lever 22 may, of course, be operated in any suitable way. But, in accordance with the present invention it is preferably operated by a cam 26 (see Fig. 5) secured to a manually operable rod 27. The cam 26 is located in a slot 28 in the shiftinglever 22 and the rod 27 is pivotally mounted in the supporting plate 24'. When the rod 27 is rotated, the cam 26 moves in the slot 28 and shifts the arm 22 laterally to move the pads 19 toward or from the brake-disk 18, and thus control the increase or decrease of the speed of the motor, as above pointed out.

hiovement of the rod 27 and the cam 26 is limited by the wall 29 of the slot 28. When the cam 26 is in the position shown in 5, further clockwise movementis prevented by the direct engagement of the cam with the wall 29, for the cam tends to pull the shifting-lever 22 directly against its pivot 23. The cam is movable anti-clockwise 180 from the position shown in Fig. 5, or until it again engages the wall 29 of the slot 28 with its other side.

Preferably, the cam 26 is formed integral with a disk 30 which embraces one side of the shifting-lever 22 adjacent the slot 28 and which is screw-threaded upon the rod 27. The cam 26 and the disk 30 are held to the supporting plate 24 by a disk orwasher 31 mounted on the rod 27 at the other side.

In case the speedregulating device is to be used in a dictating machine, where it is seldom desired to change the speed and is usually undesirable to do so, the parts are arranged as shown in Figs. 1, 2 and 3, so as to be relatively inaccessible. In this case, the manually operable rod 27 extends downwardly from the supporting plate 24 and is located beneath the topboard 13 of the machine. The cam 26 and disk 30 are screwed upon the rod 27 to engage a shoulder 32 on the rod 27 and a nut 33 is threaded upon the end of the rod 27 to hold the washer or disk 31 in proper position against the supporting-plate 24. The manually operable rod 27, at its lower end, is provided with a finger-piece 34 by means of which it may be rotated to shift the lever 22 and change the speed of rotation of the motor.

Of course, the fingerpiece 34 can be adjusted by the operator if the top-board 13 which is usually held in place by screws, is raised. But, the natural inhibition against loosening the top-board and swinging it to position where the adjustment may be made prevents this operation being done unless it is absolutely necessary, and this is a very desirable feature.

In machines, such as transcribing machines, where a single machine is employed to reproduce records recorded on several clifferent dictating machines, it is very advantageous and desirable to facilitate the opera tion of speed adjustment so that the speed of reproduction may be made to accord with the speed at which the record was made. Therefore, in such a machine. it is preferable to have the manually operable part above the top-board 13. For this purpose, the parts of the present invention are so pro-- vided that they may be used in both kinds of machines. Certain parts are, however, re-

versed and are placed in the positions as shown in Fig. 4, in which case the finger piece 34 and rod 27 extend upwardly from the supportingalate 24 and protrude through an opening 35 provided in the top board 13. The arrangement of the supporting-plate 24 and the shifting arm 22 is not changed, but instead, the nut 33 is arranged to directly engage the cam 26 and the disk 30 while the washer 31 is arranged to engage the shoulder 32 of the rod 27.

This arrangement allows the identical parts to housed in both the dictating machine and the transcribing machine, and yet permits the finger-piece 34 to be accessible in the transcribing machine while it is relatively inaccessible in the dictating machine. Of course, the rod 27 may be made much shorter than is shown in the form shown in Figs. 2 and 3, if desired.

The rod 27, in the form shown in Fig. 4,

freely passes through the opening 35, and thus does not transmit to the top-board 13, *ibrations which it may receive from the motor-frame.

For the purpose of closing the top of the opening 35, to prevent dust and other foreign material from passing through the opening 35 to the motor casing, the opening is closed by a plate 36 which is provided with a bushing 37 freely movable in the opening 38 in said plate. The bushing 37 is provided with a flange. 39 which just passes through the opening 38 and holds it therein against accidental withdrawal.

It will be seen from the above, that the present invention provides a speed-control unit which may be assembled as such, and which may be applied to the machine by the very simple operation of placing the sup porting plate 24 on the bolts 24 which support the springs carrying the motor frame.

Variations and modifications may be made within the scope of this invention, portions of the improvement-s may be used without others.

Having described the invention, what is claimed as new and for which it is desired to obtain Letters Patent, is:

1. A speed-controlling mechanism comprising a supporting-plate; a governor brake device; means for shifting the governor brake device; and means for securing said shifting means to said supporting plate; and means for securing said plate to a motor-frame.

2. A speed-control unit comprising a brake-yoke; a lever for supporting the brake-yoke; a plate for supporting the lever; and means connected to said lever and plate for shifting the lever relative to the plate to different speed-controlling positions.

3. A. speed-control unit comprising a brake-yoke; a lever for supporting the brake-yoke; a plate for supporting the lever;

and a cam between the said lever and the said plate for shifting the lever relative to the plate to dilierent speed-controlling positions.

4%. A speed-control unit comprising a brake-yoke; a lever for supporting the yoke; a plate for supporting the lever; and a double-acting cam mounted on said plate and adapted to engage said lever to shift the same to ditl'ercnt speed-controlling posi tions.

5. In combination, a motor-frame, means for supporting said motor-frame, a speedcontrol unit adapted to be supported by the motor-frame, and means adapted to both secure said speed-control unit to the motort'rame and connect the motorotrame to said supporting means.

6. A speed-control unit, comprising a supporting plate, a speed-control arm pivotally mounted on the supporting plate to move in a plane parallel to the plane in which the supporting plate lies; and manually operable means mounted on said supporting plate for shifting the speed-control arm on said supporting plate.

7 A speed-control unit, comprising a control-lever; a motor frame; means for attaching the control-lever to the motorso as to be placed in accessible position or so as to be placed in relatively inaccessible position.

9. In combination, a main-frame; a

motor-frame, means for resiliently supporting the motor-frame upon the main-- frame; speed-control mechanism mounted solely and completely upon said resiliently mounted motor-frame and comprising means extending through said motor-frame and adapted to be manually operated, the main-frame having an opening to permit the passage or said means; and a bushing loosely mounted in the main-frame and adapted to close said opening around said manually operated means.

Signed at Bridgeport, in the county of F airfield, and State of Connecticut, this 28th day of May, 1924:.

JOHN E. RENHOLDT. 

